Pancreatic elastase IIIA and its variants are expressed in pancreatic carcinoma cells

Ninety percent of pancreatic cancers are classified as ductal adenocarcinoma and are not known to secrete pancreatic elastases of the acinar enzymes. In the present study, we investigated the expression and the changes in elastase genes expressed in pancreatic ductal carcinoma cells. The expression of elastase gene family molecules in pancreatic cancer cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) method using primer sets for conservative active domains among pancreatic elastases (PEs) and neutrophil elastase (NE). The PCR products were subcloned, sequenced and analyzed. Three distinct products were isolated in pancreatic carcinoma cells using the RT-PCR analyses. The sequencing revealed that one was identical with the PE IIIA isoform, and the remaining two were alternatively splicing forms of the PE IIIA. Four of five pancreatic cell lines expressed these splicing variants in a cell-dependent manner. The present study is the first report to demonstrate the expression of PE IIIA and its splicing variants in pancreatic carcinoma cells might represent another infiltrative feature of the pancreatic ductal cell carcinoma.